Induction can soldering machine



June 2l, 1949. w. LAMPlRls 2,473,755

INDUCTION CAN SOLDERING MACHINE Filea Aug. 15, 1945 l 2 sheets-sheet 1 v June 2l, 1949. V w. LAMPlRls 2,473,755

INDUCTION GAN SOLDERING MACHINE Filea Aug. 13, 1945 -2 sheets-sheet 2 z/ .sa t 6/ I 2/ /Zl mam /a/ @tavv-me. g5

H TTU/@NEM Patented June 21, 1949 VINDUCTION CAN soLDERING MACHINE' William Lampiris, Milwaukee, Wis., assignor to Gender, Paeschke & Frey Co., Milwaukee, Wis., a corporation of Wisconsin Application August 13, 1945, Serial No. 610,543

2 Claims. 1

This invention relates to improvements in machines for joining metal parts by low temperature fusion of an alloy or a metal, and particularly to soldering the parts of a vessel which must be kept sanitary at all times.

It is therefore one object of the present invention to provide a machine by which the internally exposed joints between parts of a vessel for containing food are so made as to be, in effect, continuations of the interior surfaces of the parts so that the vessel may be readily kept sanitary at all times.

Another object of the invention is to produce a machine in which localized electric currents are induced in the parts of a metal vessel to be joined by low temperature fusion of the joining metal.

Another object of the invention is to provide a machine for soldering the joints between the parts of a metallic food container in which centrifugal force produces flow of the melted solder to form rounded interior joints.

Another object of the invention is to provide a machine in which the solder to join two metal parts is heated to the melting point while centrifugal force is applied to the parts and in which the centrifugal force is continued while the solder is cooled below the melting point.

Objects and advantages other than those above set forth will be apparent from the following description when read in connection with the accompanying drawings, in which:

Fig. l is a top plan View of a portion of the machine of the present invention with portions thereof broken away and duplicate portions omitted;

Fig. 2 is a side elevation of the machine with portions broken away and omitting some duplicated parts;

Fig. 3 is an end elevation of the machine;

Fig. 4 is a fragment, on an enlarged scale, of the structure shown in Fig. 2;

Fig. 5 is a fragment, on an enlarged scale, of the structure shown in Fig. 4 with a portion of the metal container positioned thereon prior to the beginning of the joining operations;

Fig. 6 is an enlarged fragment of a metal container showing the completed joining of the parts thereof; and

Fig. '7 is a diagram of the electrical connection for energizing the heating coils and the spinning motor and for controlling the actions of the various elements of the system in a predetermined timed sequence.

Referring more particularly to the drawings, the reference numeral I 0 designates upright mem'- CII bers joined by side members I I and end members I2 to form a frame on which is mounted a top I3. The uprights Ill are also interconnected below the top I3 by side and end members I4 and I5, respectively, for supporting a shelf I6. The parts above identified forma rigid table-like structure bearing other parts of the machine to be described. The several uprights, side and end members are shown as being structural anglesand may be magnetic material, such as iron, unless the electrical losses and heating due thereto require the use of non-magnetic material, as will be apparent from the following description. The top I3 and the shelf I6 are preferably adurable heat and electrical insulating material, such as the known cement and asbestos compositions. Such material, of course, is non-magnetic which is a desirable feature in the present instance.

It will be understood that the parts described hereinafter may be provided in any multiple desired although only two assemblages of such duplicated parts is herein indicated and only one complete structure is hereindescribed. A first frame 20 is mounted on the top I3 in spaced relation thereto, as by bolts 2l extending upwardly from the top and provided with a plurality of nuts 22 by which the spacing of the frame from the top may be adjusted. The outer edge of the frame 20 may be of any desired shape but the fram'e is made with a circular opening therethrough on which a coil of tubing 23, hereinafter designated as the outer coil, is secured on or in the peripheral edge of such opening. The frame 20 is preferably made of material similar to the top I3, and the supports 2l, 22 of the frame are preferably made of non-magnetic material. The coil 23 is made of material of high electrical and'heat conductivity and may be at least partially set into the inner peripheral edge of the frame, as shown. A ring-like tube 24 isv placed on the frame 20 and is provided with a plurality of holes through the inner surface of such tube for the purpose of directing jets of a fluid into the ring, as will appear hereinafter. Such ring-like tubel accordingly acts as a manifold by which a coolant is delivered around the entire periphery of the space deiined by the manifold.

A second frame-like member 21, which is annular in form, is mounted within and in spaced relation to the first frame. The second frame y2'! is Xed in position, as by bolts 28, securing the frame 21 on and spaced from the table top I3 and in spaced relation to the rst frame 2t. A second or inner coil 29 of tubing is mounted on or in the circumferential edge of the member by shifting of nuts on the bolts. The upperA surface of the frame 21 is preferably conical or inwardly sloping, for a purpose which will appear hereinafter.

The shelf I6 carries a drive, such vas electric motor 35, which is connected by a speed-reducing transmission, such as the belted transmission,-v

generally indicated at 36, with the input shaft 31 of a second speed-reducing transmission-genl` erally indicated at 38. The transmission 33 is preferably of the vWellknown Worm. and gear type by which a, large speed reduction is obtain able between the input yshaft '31 'fand the input shaft 3S of the second transmission. `The shaft 39 has an extension 50 inountedin andextending through a steady bearingv| Vin an aperture through the tablev top I3 centrally of Ithe second frame 21. The--sha-ftfextension 50lis threaded intermediate its endsl to receiveV a thrust nut 52 locked in place by a nut '53 and riding on a bearing plate 54,'thenut 52 and plate 54 forming a thrust bearingfor'the shaft extension and the parts 'carried thereby.l *'A hub 51y is secured on the `upper endfof"theshafti'fand lcarries a disk 58 on which are=iixedaplurality of fingers 59 secured asby 'bolts Bil-'and '6F passing through the disk and the disk' andhubrespectively.

It Will be seen that"the. Astructure described immediately above forms'raturntable driven by the motor 35 lat 'a yspeed determinedby kthe additive ratios of the several transmissions 36 and 3B. The shaft extension, the.bearin`gs therefor, the turntable hub,` the ngers'and their bolts are preferably made of non-magnetic alloys or metals and the turntable disk is preferably' a material similarto that of the tableltop I 3..` It. will be seen that the fingers. 59 extend over 4the second frame 21, to substantiallythe Ycircumference thereof, andare slightlyspaced above the upper surface of such frame..Y

The turntable is adapted .torecelve the several parts Vof a metalvesselv (see Fi'ga) for ,containingfood of which. the bottom... generally ydesignated at 66, hasA a surface'l. .forming .one wall` of the completed vessel. The vbottom is. flangeddown at 68,v and reversely flangedat. $9,l to en-v gage the edge of the container side wall 10. .Such side wall is preferably grooved,.as indicatedat 1I.,

in that portion adjacentathefbottomsurface t1Y when the bottom andtheside wall 4are in the proper relative `position.to.be joined-by soldering. A-ring ofcsolder 'l2y is `shown in place in the angle or corner .formeclby the bottom and side Wall, and such .solderismelted and caused to flow to form a joint,v as .indicated in Fig. 6 at 13. The solder may be of any desired compo-- sition, is preferably Iiuxcored, andisof a cross-y sectional size dependent-on the.. size .ofY the can parts to bejoined... At present 'a solder of thirty- :tive percent tinfandsixty-Iive-.per cent lead in-A a No. 8 wire is used 'inproductiom the melting point ofsuchA solder.being;,475'F. It will be understood that the :can parts `are tinned so that adhesion of the .solder `isasecuredfas soon vas ,4 sufficient heat is applied to the can parts and solder.

Any Well known type of device, such as either the known rotary generators or electronic generators, may be employed to induce a high frequency electric current in the coils 23 and 29. An interlinking electrical field is formed around such coils which induces an electric current in the metal can parts and the solder when placed Within such field. Such induced currents heat up all of the metal parts within the field, the heating being sharply localized in the can parts except for heat transmitted from parts adjacent the coils through the metal to other parts more remote therefrom. The coils 23 and 23 are also heated so that it is desirable to connect the coils to a source of cooling fluid, such as water from any water supply, which is circulated through the coils to prevent sufficient heating thereof to melt the coils. Any suitable compressor is connected to the air manifold 24 to provide a flow of air under the control ofa suitable valve for supplying jets of air directed on the can about its entire periphery adjacent the can bottom and side wall joint for the purpose ofv cooling the solder after flow thereof into the form` shown in Fig. 6.

A complete cycle of the operation of the machine and its associated-parts is described in the following. The can'bottom and the side wall or body areformed and tinned, the bottom flange portions 58 and 59 at that time extending as one flange Vfrom the bottom surfaceV 61.y The can body is then seatedl onv the 4vbottom to bringthe body groove 1l to the position shown'relative to the bottom surfacel. The bottom ange portion 69 is then formed over and into contact with the edge Aof the can body, as by rolling onthe die, to `produce a uniform shape and size of the angleor cornerfor receiving the solder ring, the shape and size of such solder angle depending on` a number of factors-which 'will appear hereinafter.- The solderv ring listhen placed in the angle and both the can parts to be joined andthe-solder ring are vthen preferably pre; heated to400-450 F. to reduce the length of time required for the actual soldering 'operation itself. By using a vsubstantially complete ring of. solder, the solder is uniformly distributed throughout the entire `angle between the parts to be joined.

The pre-heated canstare thenfset on the turntable andthe motor iis. started to spin the turn'- table and can at a speed Whichmaybe varied` from -100 R. P. M., the motor and drive beingsuch that approximately ten seconds are required to. come upto speed. High frequency'current is then applied to the coils 23 and 28 While thel can is spinning to complete heating of the can parts and the solder abovevthe meltingvpoint of the solder. In present production, R. F.'amperes of 480 k. c. frequency is applied.` for twenty to twenty-five seconds;` During the combined heating and spinning'step of the process the solder liqueiies and is caused'zto ovcrby centrifugal forcev into the shape `shown intl'ig: 6 of .the drawing.

The high frequency circuit to thecoils and the` motor circuit are now interruptedfand jets of air are applied 4tothe can by Wayr :of the manifold 24 While..the turntable'. is :stillspinning but 'slowly coming to vrest,'such slowing down requiring approximately twenty seconds-in the case of the motor and` drivenow in. use. The air cools the can and the solder below themelting point of the solder which solidifies 'in the form shown in Fig. 6. Air of any suitable pressure and temperature may be used,.but it has :been found that air at thirty pounds pressure and ambient temperatures is satisfactory.

It will be understood that the values above given may be varied, the only requirements being that the turntable be brought up to such speed that the fluid solder will ow into the desired form, that the solder melted only to such fluidity as to produce the desired flow under the centrifugal force produced, and that the solder be cooled while still under centrifugal force. Hence, the speed, the timeintervals, the current values, and the coolant employed will be related to the mass ofthe can parts and solder and will be Varied as such masses are varied. It will be understood that the high frequency current also induces eddy currents in the magnetic metal parts of the table coming within the field of the coils. Hence it is desirable that all metal parts coming within such field be nonmagnetic material to avoid current losses and undesirable heating in such parts.

A better understanding rof the varioussteps in the method and the relationships therebetween may be obtained by reference toy the diagram of electrical connections shown in Fig. '7 in Which symbols representing elements previously illustrated are designated with the same reference numerals as in prior figures. Alternating current is taken from a 220 volt line and is shown as passing through a plate switch 11 to a high frequency generator 16, it being understood that such showing is merely diagrammatic to indicate that the flow of current through the high frequency generator and hence its output may be interrupted by cutting olf the plate current as is well known. The high frequency cute put supplies either of two sets of high frequency coils 23, 29 by way of a double pole double throw switch 18 which is biased by a spring 19 to close one of the coil circuits and is provided with a solenoid 80 for reversing the switch to close the other coil circuit. The motors 35 are also connected with the 220 volt power line through switches shown as severally controlled by solenoids 85 and 86. And the application of air from a suitable source of compressed air 92 is controlled by solenoid-operated Valves which are separately designated 90 and 9 Thel various solenoids above identified for the two duplicate sides A and B of the machine are severally controlled by the time switches which are interlocked by a device designated |00. Many types of such timers are known and the diagram presented illustrates a timer in which synchronous motors l0||ll2 drive cam shafts H13-|04 by Which a plurality of contacts |01|08|09 H0, |I|, ||2-||3, IIB-H5 and ||6||1 are opened or closed. Power is supplied to the motors |0|I02 by way of a 110 volt alternating current line from which the various solenoids are also energized under the initial control of foot switches |2||22 severally connected with the motors IUI-|02 and the interlock |00. The interlock comprises a double throw switch biased by a spring |25 to close switch contact |24 and operable to close switch contact |23 upon energization of a coil |21. It will be seen that the above circuits are substantially duplicates for units A and B forming the complete machine above described.

It is assumed that all of the switches are in the positions shown and that contacts IIB are closed which completes a circuit to energize interlock coil |21 and reverse interlock switch |25 from the position shown. A complete cycle of operations then is as follows:

A can, with the solder emplaced and preheated, is set on the turntable of unit A. The foot switch |2| is pressed and completes a circuit through interlock switch contact |23 and through motor |0|. The motor rotates sufficiently to close contacts |01 which lock the motor in circuit even though the foot switch automatically opens when released. Contacts ||2 are then closed to bring turntable motor 35A up to speed. Contacts HI are now closed, preferably simultaneously with closure of contacts l l2, to connect the high frequency coils 23A, 29A to the high frequency generator. Contacts |09 are then closed to supply current to close the plate switch of the high frequency generator tubes so that high frequency is supplied to the coils 23A, 29A to heat the can and solder to liquefaction so that the solder may be thrown into the shape, shown in Fig. 6, by centrifugal force acting thereon. After a predetermined time contacts |69 and are successively reopened and after a further time interval contact ||2 is reopened. The contact ||4 is then closed to supply air to the manifold 24A for a given time, after which such contact is reopened and the air is automatically shut ofi. Contacts I i6 are now reopened to deenergize the interlock coil |21 which allows the interlock switch |25 to be pulled back by the spring |26 to the position closing contact |211. It will be understood that the time switch is preferably of such construction that the above mentioned time intervals may be varied as desired and that the contacts I6 may be opened at any time after opening of the contacts I|| and H2.

It is now possible to operate unit B for the reason that interlock switch |25 is back in the position originally shown so that a circuit may now be completed by closing foot switch |22 to energize motor |92. Such motor then closes its holding contacts |08 and the contacts I3 to energize turntable motor 35B. The contacts ||0 are then closed to close the plate switch by which current is supplied to the generator tubes. In view of the fact that switch 18 has been returned to the position shown by the spring 19, high frequency current is now supplied to the high frequency coils 23B, 29B. Such high frequency is again supplied for a sufiicient period of time to liquefy the solder while the can is rotating and the solder is thrown into the shape shown in Fig. 6. Contacts I0 are then reopened to interrupt the supply of high frequency current to the coils 23B and 29B. Even though contacts H3 are now also reopened, rotation of the motor 35B continues for some time and contacts ||5 are now closed to admit air to the manifold 24B by which the solder is cooled below its melting point while the can is still being rotated. After a given interval of time contacts ||3 and |5 may be either simultaneously or successively reopened to interrupt the supply of current to the motor 35B and oi air to the manifold 24B. The contacts ||1 are then closed to complete a circuit to reenergize interlock coil |21 which again changes the position of interlock switch |25 so that the cycle above described for unit A may be repeated.

Although but one embodiment of the present invention has been illustrated and described it will be apparent to those skilled in the art that various changes and modifications may be made ananas-1 thereinwithoutl .departing romfthespirit of the invention or'from the-scope'fof ythe appended. claims.'l

I claim:

1. In 4a machine. for soldering a circular base joint-in a canfa turntable-mounted for rotation in a substantially horizontalplane and adapted to receive the -base ofthe can, a single-turn stationaryinductanceheating coil concentric with the axis of rotation of the table and having a greater diameter than-the table and positioned above but adjacent to the plane of the top of the table, a second `single-turn -stationary inductance heating coil concentric with the axis of rotation of the table but being :of smaller diameter than the firstrnentionedcoil and located below said rst mentioned-coil substantially in the plane of the tabletop, and means for energizing said coils to locally `heat thatv portion `of the can disposed between said coilsand tovmelt solder placed on the interior of the can..

2. In a machine for soldering. a circular base joint ina can,- a turntable mounted for rotation in-a Asubstantially horizontal plane and adapted ot'receive the base` of the can, .a single-turn stationary inductance-heating coil concentric with the'axis of-frota'tionof the table and having a greaterdiameter than the turntable, an annular frame member disposed ksubstantially exteriorly of the coil and-supporting said coil above but adjacent tothe plane `ofrthe 'top of the table, another sin-gle-turn stationary inductance heating coil concentric With the axis of rotation` of the turntablevandfof lesser diameter than said first mentioned ;coi1;a, vsecondann-mar, frame member positioned substantial-1y.- interlorly of said-second mentioned :coil :and l supporting :said second mentioned coil substantially inthe plane of the top of the table and :below vsaid rst rmentioned coil, and vmeansv for energizingxsaid coils to locally heatthe parts of the can disposedlbetween said coils and to'melt the solder placed on the interior of thecam'` WILLIAM LAMPIRIS.

REFERENCES CITED The following references arev of record in the Curtis: fFixturesfaoilitate the use' of induction heating, American fMachinistg April 13,' 1944, page 98." 

